CIS Logo
tagline: Confidence in the Connected World

A Vulnerability in Apache Struts Could Allow for Remote Code Execution

MS-ISAC ADVISORY NUMBER:

2018-123

DATE(S) ISSUED:

11/06/2018

OVERVIEW:

A vulnerability has been discovered in Apache Struts, which could allow for remote code execution. Apache Struts is an open-source, MVC framework for creating Java web applications. Successfully exploiting this vulnerability could allow for remote code execution in the context of the affected application. Depending on the privileges associated with the application, an attacker could install programs; view, change, or delete data; or create new accounts with full user rights. Failed exploitation could result in a denial-of-service condition.

THREAT INTELLIGENCE:

There are currently no reports of these vulnerabilities being exploited in the wild.

SYSTEMS AFFECTED:

  • Apache Struts versions 2.3.36 and prior

RISK:

Government:
  • Large and medium government entities: HIGH
  • Small government entities: HIGH
Businesses:
  • Large and medium business entities: HIGH
  • Small business entities: HIGH
Home Users:
LOW

TECHNICAL SUMMARY:

A vulnerability has been discovered in Apache Struts, which could allow for remote code execution. Specifically, this issue occurs when a Java Object in the Apache Commons FileUpload library is manipulated in such a way that when it is deserialized, it can write or copy files to disk in arbitrary locations.

Successfully exploiting this vulnerability could allow for remote code execution in the context of the affected application. Depending on the privileges associated with the application, an attacker could install programs; view, change, or delete data; or create new accounts with full user rights. Failed exploitation could result in a denial-of-service condition.

RECOMENDATIONS:

We recommend the following actions be taken:

  • Upgrade to the latest version of Apache Struts immediately, after appropriate testing.
  • If unable to upgrade to the latest version, you can download an updated version (1.3.3) of the Apache Commons FileUpload library, and place it inside WEB-INF/lib, replacing the old version. This version can be downloaded at the following URL: https://commons.apache.org/proper/commons-fileupload/download_fileupload.cgi
  • Verify no unauthorized system modifications have occurred on system before applying patch.
  • Apply the principle of Least Privilege to all systems and services.
  • Remind users not to visit websites or follow links provided by unknown or untrusted sources.

REFERENCES:

Get Email Updates When Cyber Threats Like This Arise

Arrow Subscribe to Advisories

Protect Your Systems from Cyber Threats Like This

CIS Controls That Help Avoid This Issue Arrow CIS Control 3: Continuous Vulnerability Assessment and Remediation Arrow CIS Control 18: Application Software Security